Sorry for the delay in posting pictures. Computer issues have put me days behind in many things. After six years of faithful service it is getting time to replace the laptop that has served me well, all things considered.

I'll wait until Windows 10 comes out in about three weeks though.

I note that there is a tendency there to have a wave form not uncharacteristic of that found between the two coils of an IFT where the coupling can produce a wave with a "U" or "V" in it so there is an off chance that there is a transformer involved & the issue is before it?

Isn't speculating good brain exercise... If I find a photo (that I have) of what I mean I will send it to Brad.

Marc

Interesting speculation.

Yesterday I walked around with my portable receiver on a DF exercise outside of the complex and I was able to detect similar RFI on two other kiosk substations in the street -- one of them appears to be quite old -- so I guess there's the possibility that the source is indeed an Ausgrid transformer in the locality.

I made a follow-up call to Ausgrid this morning and my job is awaiting allocation of a technician with suitable mains monitoring equipment. If I haven't had contact regarding a visit by Monday afternoon, I'm to call back.

One other thing I thought of could be the ripple sent over power lines that allow remote control of off peak loads. I never bothered to ask anyone who knows how strong these signals are and if they affect radio reception.

One other thing I thought of could be the ripple sent over power lines that allow remote control of off peak loads

I know those tones. They come in short bursts and are not unlike musical notes.

Again, what I am experiencing is 24/7 continuous and relentless hash. (See frequency analysis chart in post #24).

I am victim of an unwanted 'dirty' transmitter of some kind.

Now that switching tone is interesting, for the purpose of more speculation & research. Where's the generator? What's its frequency? Is it on a Zellweger timer, that is stuck "on" some of them have motors.

I do hope that eventually, we will see who gets the gong, for guessing this secret sound.

If you know its being used somewhere, it may be interesting to have the CRO poised to see the waveform.

https://en.wikipedia.org/wiki/Zellweger_off-peak



Marc

All of the electricity meters in this industrial complex, built in 2012, are "smart" meters. I'm not aware of anybody with a Zellweger type offpeak arrangement (I have not noticed any such devices in the switch room).

However, who knows what's installed in neighbouring buildings? As mentioned, I can detect this hash in other parts of Ausgrid's supply line in the street -- uphill from me, but not downhill from me.

The downhill buildings are fed from a different set of overhead wires. Up to and including my complex, there are two sets of overhead wires on the poles; one atop the other. After me, there is only one set of overhead wires.

The old 24 hour timers (powered by a synchronous motor) were the original way off peak loads were controlled but it was never truly successful because with the change of the seasons the supply authorities would have had to get meter readers to change the on and off sequences on every timer as meters were read in spring and autumn to stop peak and off-peak loads overlapping. To an extent this was tried in NSW and probably other states too but the remote control technology with the ripple signals meant full control over every household with an off-peak load connected without the labour-intensive manual handling of timers, and having to reseal each timer after adjustment. Timers also fell out of whack when there were blackouts and these were quite common (by today's standards) in Sydney in the 1970s mainly as a result of industrial disputes.

I've never tested synchronous motors for interference so I am not sure what they'd give off in that regard.

When I was a kid, our house had gravity feed offpeak hot water. A terrible system for a family -- last to shower got a cold one, and always pathetic pressure from the tank to boot.

I could always hear the associated on/off tones in our TV.

There were a couple of varieties of those HW meters. I did note that the one here on the old house had a extra spring mechanism like a regulator clock & it would not stop until the spring wound down.

Can't quite see a synchronous motor generating RFI if its a squirrel cage type like in clocks.

My point would be with the transmitter, if there is one, it may be at the main substation, feeding several smaller units. Now if such a thing is there switching things on & keeping them on, should that not be reflected in extra load on the feeders which one would think would be picked up as abnormal?

Marc

The large tanks in roofspaces were quite common but they did have some drawbacks. They were quite large but they were not stored pressure types. They were just a copper tank with a layer of insulation and an outer skin of zinc-plated steel. The water was fed to the tank by a small external cistern and there was a huge element, typically about a metre long, inside the tank to heat the water.

The upside is that they held lots of water, or at least the larger models did. One downside was that thermal efficiency was dreadful. Another downside is that if the cistern's float valve failed and no-one was home, the water would drop through the overflow into the tank stand's drip tray and then drain to the outside of the house through the eave. It would just keep going until the householder got back home. The other downside is that there was only one element. This meant that if the county council had either forgotten to or was unable to turn on your heater that night there'd be no more hot water for at least 12 hours.

The 400 litre 'Big Blue' twin element stored pressure heaters from Dux and Rheem sorted this problem out in later years.

Ahhh yes, I almost forgot - yeah, the head pressure in only about two metres of 'fall' in a half inch water pipe ain't all that great. In some areas that had more up to date water board connections the head pressure from the water heater had to compete with mains pressure from the cold water which was directly connected to the metered water supply. I've seen cases of this causing back pressure on the hot water at the point it is mixed with the cold near the shower rose, which also meant a cold shower even if the tank was chokkas with steaming hot water. Some people got around this by installing a cold water tank as well and this was also more common in places like hospitals.

Any hints on this greatly welcomed!!

I'm looking at replacing incandescents and fluoros with LEDs wherever practical, and am accumulating experience. The 240v LED tubes and bulbs all have flimsy little PSUs built into them and you have to wonder whether those switching components will last for the advertised life of the LEDs themselves - I doubt it.

I have one 4' LED tube replacement in a bathroom - the light and performance are excellent, but the PSUs have a permanent little whine, about the level of tinnitus! No whining problem with LED bulbs so far.

For my workshop, where AM reception is already poor, RFI is a problem. I'm thinking of setting up a reasonable 12v PSU, possibly an ATX PSU with good shielding, to provide a 12v DC source purely for lighting, or using 12v AC supplies designed for halogen downlignts, to drive as many of those halogen-replacement 12v LED bulbs as necessary. I think they contain only current-limiting resistors and no switching, and use the individual LEDs themselves, arranged in alternate polarities, to perform half-wave rectification on each pole so you get no discernible flicker. Fittings and tails are readily available or adaptable from discarded halogen installations. Lower voltage has some safety appeal in that environment.

One more issue with LED lamps is that if they are not well diffused they cast a very uniform beam that can produce sharp reflections and shadowing in confined spaces, such as the insides of crowded chassis. I always go for as much diffusion as possible now, as it seems to be easier on the eyes.

Maven

For the wattage of some of these globes one does wonder if a regulator like LR8 with pass transistor could be built? It would likely use a lot less resources to make it & may well be competitive at low power?

LR8 will take up to 450VDC input. & I don't see a need for massive filters with a globe. One could radiate heat the same way a valve does. It can be rigged as a current regulator.

I also wondered at the efficiency & Greenhouse ramifications of feeding a string of diodes with a barretter the way some transformerless AC/DC sets did on the filaments?

Marc

LED globes are very good. I recommend warm white as the colour very closely matches incandescent globes and is thus less harsh than what they call cool white, which has too much blue in it. Also, contrary to popular belief, a higher colour temperature doesn't always mean higher light output. It can often be the reverse.

The only downside to LED globes is that they are fragile. The glass is very thin and because it is not subject to a vacuum it will break much easier than the older lamps. Looking back, the only LED globes I've needed to throw away are those I've dropped. The rest are still in service after up to three years.

I can't comment on RFI from them as I haven't measured it, nor have I really noticed any. You can still buy fancy round incandescent globes if RFI is an issue in a particular part of the home. These are usually only available up to 40 watts though.

I actually bought a LED globe recently of 4Watt It has four bars facing down like the radiators on the phone towers: The whole being enclosed in a roundish retro envelope.

I doubt there are a variety of bits in it & hopefully they have come to there senses & actually made a string of them that add up to mains voltage? If they are in an envelope with no oxidant, one would like to think that that will lengthen their life.

Marc